Fusible link.



S. M. MARSHALL.

FUSIBLE LINK. v APPLIOALTION'IILED NOV.16, 1912.

1,080,228, Patented Dec. 2, 1913.

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STEPHEN M. MARSHALL, CLINTON, MASSACHUSETTS.

rUsIBLn LINK.

Specification of jLetters Patent.

Patented Dec. 2, 1913.

Application filed November i6, 1912. Serial No. 731,872.

To all whom it may concern:

Be it known that I, STEPHEN M. MAR- SHALL, a citizen of the United States, residing at Clinton, in the county of WVo-rcester and State of Massachusetts, have invented a new and useful Fusible Link, of which the following is a specification.

This invention relates to a fusible link f3):- use in fire prevention apparatus and the li e.

. The principal objects of the invention are to provide a construction reduced to a very simple form in which the fusible metal when in place not only resists a direct pull for separating the parts of the link, but it also affords a resistance to prevent the links coming into a position such as to permit them to be separated, whereby the tendency to cold-flow is very materially reduced, and a fusible material affording comparatively slight resistance can be employed if desired.

The invention also involves a construction in which a direct pull for separating the parts of the link necessarily results first in swinging the links with respect to each other, and the fusible metal is located in position to resist this swinging action. In this way relatively great resistance on the part of the fusible material is secured and yet when it commences to fuse it will permit the parts to swing and separate.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which- Figure 1 is a face view of a complete link with the fusible metal in position; Fig. 2 is a view of the same parts showing the parts in the first position they assume after the fusible metal is fused; Fig. 3 is a face view of one of said parts; and Fig. 4 is an edge view of the link as shown in Fig. 1.

The link is illustrated in a simple form in which it comprises two parts A and B. The part A is shown more clearly inFig. 8 and comprises a flat plate having a perforation a at one end for receiving a flexible connection or the like, and provided with two studs or integral projections a and a separated from each other and located near the other end. The centers of these two studs are shown substantially in alinement with the center of the perforations (1. Between the two studs preferably is located another perforation at The part B has a perforation b for the same purpose as the perforation a. It is also provided with a longitudinal slot 5, but not exactly in line with the axis thereof. At the inner end of this slot is an offset 5 which constitutes the end of the slot. This slot and its offset are both of a width sufficient to receive one of the studs on the other piece. The outer edge of the offset affords a shoulder b for a purpose to be mentioned hereinafter.

WVhen the parts are assembled the stud a is received in the offset 6 behind the shoulder 5 while the stud a is received in the slot 5 near the outer end thereof. The space between these studs and surrounding them is filled with a body of fusible material C' which extends through the perforation a and also preferably forms a uniting layer between all the surfaces of the parts A and B which are in contact with each other. Any desired fusible material can be used for this purpose, as for example, soft solder. It will be seen that by projecting into the perforation a it is located in position mechanically in addition to the hold which the solder has on the metallic surfaces with which it comes into contact.

It will be obvious that the link is intended to be used in a place in which flexible connections or the like as D are connected through the perforations a and .7) and exert a direct opposite pull for the purpose of longitudinally separating the two parts of the link. It will be seen further that with the stud a in the extremity of the offset 72 the direct line between the centers of the perforations a and 5 comes to one side of the stud a and also preferably to the same side of the stud 64'. Therefore the pull on the two connections D has not only a direct separating pull on the two parts, but it also tends to swing them with respect to each other about the stud 0. as an axis. It may be considered, for example, that the part B of the link is given a tendency to swing about the stud a as a center for the purpose of bringing the stud a out of the offset 12 into the longitudinal part of the slot 5. It will be seen furthermore, that on account of the shape of the offset 6 the solid metal of the link in the shoulder 19 at the upper side of the same absolutely prevents the longitudinal separation of the two parts until this swinging action has taken place to bring the stud a entirely out of the slot 1 Therefore, a solid resistance is secured against this action, formed by surfaces of hard metal which is relatively non-fusible. It is obvious, therefore, that in order to separate the two parts of the link without properly fusing the fusible metal it will be necessary to displace the soft metal which comes directly under the stud b in Fig. 1, and this can be done only at a great disadvantage due to the leverage which this construction atfords. Therefore this small body of soft metal directly under this stud, while in a cold state, affords an effective resistance against the tendency of the twoparts to separate, and any force that is applied to the two parts to separate them longitudinally will be greatly reduced in effect when applied to this body of soft metal. In this way it will be seen that the resistance to separation is greatly increased and that the danger of cold flow is practically eliminated. Yet when the soft material starts to melt the resistance to this swinging action is entirely removed and the shoulder b at the rear of the stud a does not offer any material resistance to the swinging of the links with respect to each other and their longitudinal separation will obviously take place very readily once the swinging action has occurred.

Although I have illustrated and described a simple form of the invention, I am aware of the fact that the principles thereof can be carried out in other ways without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to all the detalls of construct-ion, but

WVhat I do claim is 1. As an article of manufacture, a link of the character described comprising twomembers, one having a projection and the other a slot into which said projection is adapted to project when the two members are assembled, the wall of said slot having a shoulder position to resist the direct separation of said members, whereby separation can occur only after a relative swinging motion of the members, to move the projection from behind said shoulder with the member on which the projection is located, and readily fusible metal in said slot for holding the two members together and resisting the swinging motion.

2. As an article of manufacture, a link of the character described comprising two flat members, one having a fixed projection and the other a slot into which said projection is adapted to project when the two members are assemblechthe wall of said slot having a shoulder in its own plane in position to resist the direct separation ofsaid members by motion directly apart in their own planes, whereby separation can occur only after a relative swinging motion of the members in their own planes and a later transverse longitudinal motion, and readily fusible metal in said slot for holding the two members together and resisting the swinging motion.

3. As an article of manufacture, a fusible link comprising two members, one having a pair of projections thereon near one end, the other having a slot extending from one end and having an offset at the rear end of the slot for receiving said projections, said members having means for the application of external connections at their ends opposite the studs and slots respectively, and a body of fusible material introduced into said slot between said projections and extending between the projections in the offset and the opposite wall of the slot.

4. As an article of manufacture, a fusible link comprising two fiat members, each having a hole therethrough at the outer end, one having two projections, substantially in line with the hole thereof, the other having a slot for receiving said projections and provided with means. whereby when a force is applied at said end holes for separating said members they will be caused to swing on one of said studs as an axis before they commence to separate.

5. As an article of manufacture, a fusible link comprising a member having two projections near one end thereof separated from each other, a second member having a slot extending longitudinally from one end with an offset at its inner end, one of the rojections being located in the outer en of the slot, and the other in the offset, said members having means near their outer ends for the application of a force for pulling the members apart, and said projection in the offset being located at one side of a line connecting said means.

6. As an article of manufacture, a fusible link comprising a member having two proections near one end thereof, a second member havmg a slot with an offset at one end,

one of the projections being located near the end of the slot, and the other in the offset, said members having means near their ends for the application of a force for pulling the members apart, and said projection in the offset being located at one side of a line connecting said means, whereby the exertion of a force tending to separate the two members longitudinally will first causethem to swing to bring the inner projection into the bony of the longitudinal slot, and a fusible material located in said slot between the 7 projection located in the offset and the opposite wall of the slot.

7. As an article of manufacture, a fusible link comprising a member having two projections near one end thereof separated from each othe a second member having a slot with an offset at its end, one of the projections being located in the end of the slot, and the other in the offset, said members having means near their outer ends for the application of a force for pulling the members apart, and said projection in the offset being located at one side of a line connecting the centers of said means, the first named member having a perforation therethrough between said projections, and a body of fusible material substantially filling said slot and extending into said perforation.

8. As an article of manufacture, a fusible link consisting of two flat members, each having means at the end for the attachment of a connection, and one of said members having a shoulder engaging a fixed part of the other, whereby upon a force being applied to separate them they must first swing relatively to each other in their own planes and then move longitudinally away from each other, and a body of fusible material for connecting said members located within the boundaries of one of the members in position to engage the surface of said fixed part and resist said swinging action.

9. As an article of manufacture, a fusible link comprising two flat members, one having a projection thereon near one end, and the other having a longitudinal slot extending in from one end and having an offset at the inner end of the slot, the projection being located in the offset when said members are assembled, said members having means near their outer ends for the application of a force for pulling the members apart, and said projection being located at one side of a line connecting said means, and fusible material located in said slot.

In testimony whereof I have hereunto set my hand, in the presence of two subscribing witnesses.

, STEPHEN M. MARSHALL.

Witnesses:

UHEsrnR A. Goon, HARELD AsHnY.

Copies of this patent may be obtained for five cents each, 'by addressing the Commissioner of Patents, Washington, D. G. 

